Underbalanced Drilling (UBD) has many benefits, including the mitigation of skin damage during the drilling process. How this reduction, or prevention, of skin damage actually benefits a reservoir and the overall recovery and life of the well is debatable. The aim of this project is to confirm the advantages of UBD by simulating reservoir damage and the effects of drilling fluids in overbalanced, or conventional, drilling practices on a core and compare the results to an undamaged case.